This invention relates to irrigation sprinklers, and more particularly to a new and improved short range sprinkler nozzle intended to produce a low pressure, small droplet sized water spray for close-in watering.
Many large size sprinklers employ multiple nozzles for projecting water sprays different distances from the sprinkler to more uniformly water the area intended to be covered by the sprinkler. Typically, such sprinklers may employ a relatively large bore or "range" nozzle which can project a relatively high velocity, large volume water stream fifty to a hundred feet or more from the sprinkler, and a short range or "spreader" nozzle which is intended to project a smaller volume water stream a shorter distance from the sprinkler to irrigate the area between the area covered by the range nozzle and the sprinkler body. In some instances, such sprinklers may also employ a third, intermediate range nozzle for projecting a stream an intermediate distance to cover an area between that covered by the range nozzle and that covered by the spreader nozzle.
In conjunction with the use of a spreader nozzle, it is important that the stream produced fall-out early and uniformly to enhance water distribution, and that the size of the water droplets be relatively small to prevent the irrigated soil from being compacted by the falling water drops. Typically, such spreader nozzles have employed the techniques of producing a high pressure and/or high velocity water stream from the nozzle which cause the stream to expand rapidly upon exiting the nozzle and thereby produce a fine spray of relatively small size droplets.
While spreader nozzles employing such techniques have met with considerable success, one problem that has long been present is that the fine, almost mist-like spray produced by many spreader nozzles is susceptible to being blown by wind, and suffers from considerable evaporation before reaching the ground. As will become apparent hereinafter, the present invention provides a short range or spreader nozzle which minimizes the effects of wind and evaporation while providing a highly reliable and effective means for producing a low pressure, small droplet sized spray for close-in watering.